The alkaline earth metals forming ionic oxides are

Options

A. `BeO`
B. `MgO`
C. `CaO`
D. `SrO`

Explanation

To determine which alkaline earth metals form ionic oxides, we need to analyze the properties of the oxides formed by these metals. Here’s a step-by-step solution:

### Step 1: Identify the Alkaline Earth Metals
The alkaline earth metals are found in Group 2 of the periodic table. They include:
- Beryllium (Be)
- Magnesium (Mg)
- Calcium (Ca)
- Strontium (Sr)
- Barium (Ba)
- Radium (Ra)

### Step 2: Understand Ionic vs. Covalent Oxides
Ionic oxides are formed when a metal reacts with oxygen and the metal has a high charge density, leading to the formation of ionic bonds. Covalent oxides, on the other hand, are formed when the metal has a smaller ionic radius and higher charge density, which leads to stronger polarization of the oxide ion (O²⁻).

### Step 3: Analyze the Oxides of Alkaline Earth Metals
- **Beryllium Oxide (BeO)**: Beryllium has a small ionic radius and a high charge density, which leads to significant polarization of the oxide ion. Therefore, BeO is covalent in nature.

- **Magnesium Oxide (MgO)**: Magnesium has a larger ionic radius compared to beryllium, and it forms a stable ionic bond with oxygen. Thus, MgO is ionic.

- **Calcium Oxide (CaO)**: Calcium, being larger than magnesium, also forms an ionic bond with oxygen. Therefore, CaO is ionic.

- **Strontium Oxide (SrO)**: Strontium continues this trend and forms an ionic bond with oxygen, making SrO ionic.

### Step 4: Conclusion
From the analysis, we can conclude that the alkaline earth metals that form ionic oxides are:
- Magnesium Oxide (MgO)
- Calcium Oxide (CaO)
- Strontium Oxide (SrO)

Thus, the correct answer includes magnesium oxide, calcium oxide, and strontium oxide.

### Final Answer
The alkaline earth metals forming ionic oxides are:
- Magnesium Oxide (MgO)
- Calcium Oxide (CaO)
- Strontium Oxide (SrO)